After completing Breakthrough Mode, it is possible to Promote the characters used to Elite 10 and Level 60.

For certain battles, such as either Bonus Battle(s) in Standard Battle or in Challenge Mode, this time there'll be a specific way to let players know between a regular match, and a match against the "Mini-boss" and Boss (underlined in red below that character).

For certain characters, their passives' descriptions have been "updated" to add "BOSSES ARE PROTECTED"! At this point, the only characters that have this are The Flash/Regime, Raven/Prime, and The Joker Unhinged/Suicide Squad. It should be noted that this does not in any way change the mechanics of the characters' passives. Rather, it updates the description with the mechanics of the passive. For instance, Joker has never been able to control Bosses since release, and now his description has been updated to show that (no actual change in his passive).

Raven/Prime's heavy combo has also been changed so now that it knocks down enemies, rather than simply knocking them back like it used to.